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This appears to be it. The secret? Don't worry about the stop bits. They're just processing time. Latch onto the next start.

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This commit is contained in:
Thomas Harte 2016-11-03 07:34:48 -04:00
parent 827a919368
commit e9f1a6a79d
2 changed files with 26 additions and 14 deletions
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37
Machines/Oric/Oric.cpp
View File

@ -72,7 +72,6 @@ unsigned int Machine::perform_bus_operation(CPU6502::BusOperation operation, uin
}
_via.run_for_cycles(1);
_via.tape->run_for_cycles(1);
_cycles_since_video_update++;
return 1;
}
@ -197,6 +196,7 @@ void Machine::VIA::run_for_cycles(unsigned int number_of_cycles)
{
_cycles_since_ay_update += number_of_cycles;
MOS::MOS6522<VIA>::run_for_cycles(number_of_cycles);
tape->run_for_cycles(number_of_cycles);
}
void Machine::VIA::update_ay()
@ -213,7 +213,8 @@ Machine::TapePlayer::TapePlayer() :
_is_catching_bytes(false),
_cycle_length(0.0f),
_was_high(false),
_queued_lengths_pointer(0)
_queued_lengths_pointer(0),
_shift_register(0)
{}
uint8_t Machine::TapePlayer::get_next_byte(bool fast)
@ -222,14 +223,16 @@ uint8_t Machine::TapePlayer::get_next_byte(bool fast)
_is_catching_bytes = true;
_bit_count = 0;
while(_bit_count < 13)
_was_high = get_input();
_queued_lengths_pointer = 0;
_shift_register = 0;
while(_bit_count < 10)
{
process_next_event();
}
_is_catching_bytes = false;
printf("%02x ", (uint8_t)(_shift_register >> 3));
return (uint8_t)(_shift_register >> 3);
return (uint8_t)(_shift_register >> 1);
}
void Machine::TapePlayer::process_input_pulse(Storage::Tape::Tape::Pulse pulse)
@ -243,7 +246,7 @@ void Machine::TapePlayer::process_input_pulse(Storage::Tape::Tape::Pulse pulse)
if(is_high != _was_high)
{
// queue up the new length
_queued_lengths[_queued_lengths_pointer] = (int)(_cycle_length * 4800.0f + 0.5f);
_queued_lengths[_queued_lengths_pointer] = _cycle_length;
_cycle_length = 0.0f;
_queued_lengths_pointer++;
@ -252,18 +255,21 @@ void Machine::TapePlayer::process_input_pulse(Storage::Tape::Tape::Pulse pulse)
{
if(_queued_lengths_pointer >= 2)
{
if(_queued_lengths[0] == 1)
float first_two = _queued_lengths[0] + _queued_lengths[1];
if(first_two < 0.000512*2.0 && _queued_lengths[0] >= _queued_lengths[1] - 0.000256)
{
int new_bit = 0;
if(_queued_lengths[1] == 2) new_bit = 0; else new_bit = 1;
_shift_register = (_shift_register >> 1) | (new_bit << 12);
_bit_count++;
memmove(_queued_lengths, &_queued_lengths[2], sizeof(int)*14);
int new_bit = (first_two < 0.000512) ? 1 : 0;
if(_bit_count || !new_bit)
{
_shift_register |= (new_bit << _bit_count);
_bit_count++;
}
memmove(_queued_lengths, &_queued_lengths[2], sizeof(float)*14);
_queued_lengths_pointer -= 2;
}
else
{
memmove(_queued_lengths, &_queued_lengths[1], sizeof(int)*15);
memmove(_queued_lengths, &_queued_lengths[1], sizeof(float)*15);
_queued_lengths_pointer--;
}
}
@ -276,3 +282,8 @@ void Machine::TapePlayer::process_input_pulse(Storage::Tape::Tape::Pulse pulse)
_was_high = is_high;
}
}
void Machine::TapePlayer::run_for_cycles(int number_of_cycles)
{
if(!_is_catching_bytes) Storage::Tape::BinaryTapePlayer::run_for_cycles(number_of_cycles);
}

3
Machines/Oric/Oric.hpp
View File

@ -102,6 +102,7 @@ class Machine:
public:
TapePlayer();
uint8_t get_next_byte(bool fast);
void run_for_cycles(int number_of_cycles);
private:
bool _is_in_fast_mode;
@ -110,7 +111,7 @@ class Machine:
float _cycle_length;
bool _was_high;
int _queued_lengths[16];
float _queued_lengths[16];
int _queued_lengths_pointer;
int _shift_register;